This is a Career Development Award proposal for Dr. Annette Fleckenstein. She is a Professor of Pharmacology and Toxicology at the University of Utah. She has been active in drug abuse research for 13 years and has made important contributions to elucidating the effects of psychostimulants on dopamine (DA) transporter (DAT) and vesicular monoamine transporter-2 (\/MAT-2) regulation and function, especially as related to the neurotoxic effects of the amphetamines. The applicant is a current K02 recipient, and this has permitted the applicant to dramatically decrease her institutional responsibilities and devote 75% of her time to research and professional development as described in her application. Renewal of this award is requested so that the applicant can continue directing research which test the hypotheses that: 1) methamphetamine (METH)-induced DAT complex formation is associated with, and may contribute to, the dopaminergic deficits caused by the stimulant; 2) methylphenidate uniquely affects monoaminergic vesicular function and distribution by a mechanism that includes novel shifts in VMAT-2M-mediated DA transport kinetics; and 3) latter-stage events related to intracellular DA management are critical for the persistent dopaminergic deficits caused by METH, and that these events are absent in both adolescent rats and those treated with METH during development. Continued support of this K02 award will not only allow the applicant to expand upon these studies, but also develop expertise in technologies new to her laboratory. In particular, funding of the K02 will facilitate the incorporation of self-administration technology into her laboratory that will permit investigation as to whether transporters are altered in that clinically relevant paradigm. Further, renewal of the K02 will allow the applicant to continue and expand interdisciplinary collaborative efforts with researchers both within and outside of the University of Utah as delineated in the proposal.